Speed reduction drive mechanism



June 22, 1965 A. M. GORFIN 3,190,149

SPEED REDUCTION DRIVE MECHANISM Filed 001;. 5, 1962 s Sheets-Sheet 1 N X l E m 0C m m T 7 w w n \m.\/ m M/ June 22, 1965 Filed Oct. 5, 1962 A. M. GORFIN SPEED REDUCTION DRIVE MECHANISM 3 Sheets-Sheet 2 June 22, 19 65 A. M. GORFIN 3,190,149

SPEED REDUCTION DRIVE MECHANISM Filed Oct. 5, 1962 3 Sheets-Sheet 3 ALE'EVVZNTCE'EN M 02 FIG 10 BY ATIUZA EX.

i 3,190,149 I SPEED REDUCTION DRIVE K Alex M. Gorfin, 490 West 'End -Ave., New York, NX. Filed Oct. 5,1962, SernNo. 228,556. V

r '16 Claims (Cl. 7 4 805) This inventionfrelat es to'a speed reduction drive mech anism for converting power at high'sp'eedand relatively.

low torque tolow speed and correspondingly higher torque; and more particularly to a reduction mechanism for use where a transmission ratio is required.

Inthe latter event, that is, where Ithe'desired speed of the power output shaft is very much lower. than the speed of the power input shaft (usually the shaft of an electric motor) the speed reduction transmissions of the prior artinvolved several important disadvantages. If the gearing comprised conventional spur or bevel gears, the high' transmission ratio required an extensive gear chain with a large number of gears, thereby resulting in a device which was large, bulky and expensive. Use of a worm gear and pinionreduced the size .of thetransrnission unit somewhat, but wasiinei'ficient and required replacement of the worm gear which wore o'ut too frequently. The, use of a belt or chain engaginga pulley or sprocket was limited tosmall transmission ratios up to about 8: 1..

a high transmission ratio but ple, compact and inexpensive.

This object is achieved. by anovel arrangement zwherefi in the rotation of the motor shaft is' converted into'acombined oscillatory and reciprocating translatory motion of a driving gear whereby the teeth of the gear will pro-.; gressively enter into and out of engagement with a series of spaced openings in acontinuous curvilinear driven element extending around the'g'ean; This progressive inter-- engagement causes the driven element to be displaced a distance of one driving gear tooth space for each rotation of the motor shaft. ee

Similar arrangements have beenknown in the. prior art where the driven element was in the form of an internal gear surrounding-the driving gear; This arrangementcould not provide. as high a transmission ratio as the The'tra nspresent invention for the following reasons. mission ratio may be calculated as: Ratio: Number of teeth on" outer gear 7 i Difference betweennurnber of teeth on outer and inner gears When using standard tooth forms, the prior art arternalgear required for proper meshing that this internal gear have no fewer than three more'teeth than the inner driving gear. By using specifl short tooth forms,*it was 7 possible to construct theouter internal driven gear with only two more teeth, thereby increasingthe transmission ratio by fifty percent. j I

However, by the-novel-construction of the present invention, thedriven element may have inelfect only one more tooth than the drivinggear, thereby providing a transmission ratio two or three times as large'as those of saidpriorart arrangements. f

. Inone form of the invention the continuous curvilinear driven element is in the formiof a cylindrical 'wall'sur I 65 roundingithe'driving gear and having a series of openings therethroughfor receiving the gear-teeth. In another embodiment of the invention the driven element is inthe 1 It is therefore a primaryi object. of the-present invention to provide. a speed reduction drive mechanism having.

tiono f the chain; and which is nevertheless sim- FIG. 10 is an enlarged view showing'the. engagement;

Qther advantages o f the invention are inherent in thestructure disclosed or will become apparent to thoseskilled in the art as the description proceeds in connectionwith the accompanying drawings wherein:

FIG. 1 is a vertical sectionalview taken substantially online 1-1,of FIG. 2 and shows one form of the invention;

FIGQ 2 is a vertical .sectional; view taken substantiallyon line 22 of FIG. 1; I I

FIG. 3 is a horizontal sectional view taken substantially on line 3-3 of FIG. 1

FIG. 4 is a vertical sectional view taken on line of FIG. 5 and shows-a-modilied form of the invention wherein the driven element is in the form of a continuous tape;

FIG. 5 isa vertical sectional View taken substantially- (m the line s- 5 of FIGA; p

FIG. 6 is a plan view of a portion of the tape;

FIG. 7 is a -vertical sectional view taken on line 7-7 of FIG. 8 and shows still another modified formof the: I invention wherein the driven elementis in the form of. a

chain; 1

, FIG. 8 is a vertical on the line 8-8 of FIG. 7; i

sectional view FIG. 9 is a horizontal sectional view taken substan tially on theliIie-99 of FIG. 7 and shows the construe-I of the chain with the V;-groo ve offa pulley.

' The embodiment of the; invention disclosed in FIGS. 1 to.3 inclusive will-fi rst bedescribed. These figures disclose aspeed; reduction drive mechanism indicated'general lyi the reference numeral 12 and shown mounted to one end of a motor 13. The latter comprises a housing'14 having at ,pne end an. enlarged circular boss 15 w provided with a suitable opening through which the motor '50 rangements-wherein the outer driven element wasan in- 1 0 tionary support or houslng comprising a'pair of fixedspaced housingplates 26, 27 which are held in spaced.

form of a flexible tape orbelt having spaced openings thereinifotr receivably engaging. the teeth. In a third modification of the V element in' the form of a flexible chain.

vention there. is disclosed a driven" project through elongated slot 2 5 formed in gea r 2 2 fro-- shaft ldoutwardly projects.

. Speed reduction drive mechanism 12 comprises a eye; lindrical sleeve member 17 mounted on motor shaft 16.; andzsecured fixedly thereto by a set screw 18. Formed" integral withrthe inner end of member 17 is a circular eccentric disk 19rhaving a center 20 displaced s eccentrically from the axis 21 of motor shaft 16.

A driving gear 22 is provided with a central circular opening 23 which engageably receives eccentric disk 19, Extending entirely around the periphery of gear 22 are a'.'

I series of teeth 24. Gear 22 is further provided'with aj somewhat elongated slot 25 which extends entirelytherethrough and'also radially with respect to the 20 of gear 22. p s e I Gear Y22 and eccentric disk 19 are located within a staapart relation by four spacer sleeves '28 spaced at intervals. Three of the spacer sleeves 28 extend through circular holes 29 formed through the webportion 30 of gear 22. The fourthsleeve 28 extends through slot 25. 3,

A bushing 31 extends through each of the sleeves 28 and ings 36 provided'in a circular spacer plate 37 which abuts against end face 35 0f motor. housing 14 so as to maintainrear cover plate .27 in'spaced relation with respect to. hjousingface35 Each of the-bushings 31' is provided atitsopposite ends with laterallyextending flanges 39* and a washer 40 extends between the forward flanges 39 and slo tt edhea d 33 of bolt 32. I l

The bolt 32, bushing 31, and spacer sleeve28 which 7 Patented June 22,1965

taken substantially engaged thereby is a cylindrical driven element 41 com- 7 a .pin extending through said housing 14;

prising a thin'cylindrical wall havingia series of openings 42 spaced entirely therearound for engageably receiving the teeth 24 of gear 22. Cylindrical drive element 41 is preferably of metal and'has its' opposite edges securely embedded in the respective halves 43, 44 of a pulleytiudicated generally at ,45. The pulley halves 43, 44' are held together by a tubular metal element 46 and are provided with sloping wall portions 47, 48 respectively for engageably receiving a V-shapedbelt 49. :The innerper'ipheries of pulley halves43, 44 are provided with bearing surfaces 50, 51 which slide upon stationary cylindrical bearing elements 52, 53 fixedly mounted to the outer edges of plates'26, 27 respectively. s V j i Speed reduction drive'mechanism 12 operates in the following manner. Energization, of electric motor '13 causes rotation of motor shaft 16' along with sleeve mem- 'ber 17 securedthereto 1 Eccentric disk 19 is thus rotated about shaft axis 21" and thereby drivesgear 22. The latter, due to the engagement of its slot 25 with the fixed pin structure consisting of elements 28, 31, 32 undergoes a' combined oscillating and reciprocating motion in respouse to rotation of eccentric disk 19 about shaft axis 21:

7 Each of gears122, 163'Iis provided with an elongated radially extending slot as at 25,125 respectively. Afbolt 32 together with a bushing 31 and a spacer sleeve 28,ras

described above with respect to the modification of FIGS.

1 to, 3, extend through slots 25,125 and alsolthrough housing plates-26, 27 and mounting plate 37 to maintain said plates in fixed relation on the sideface 35 ofmOtor It will thus be-seen tthat the engagement of slots 125 with the pin assemblies 28, 31, 32 permits gears 122,

161 to simultaneously oscillate about the axis of bolt 32 and undergo reciprocal translatory movement in a radial direction as'eccentrics 1'19, 160 are rotatedabout theaxis 7 21 of shaft 16. Due to the, factrthat the eccentricity or throw of eccentric '119is 180 from that of eccentric V 160, the motions of gears 122, 161 will be identical but displaced one-half cycle'or 180 from each other. 7

Riding on the cylindrical bearings;52, 53securedtd the outer fperipheriesof housing plates 26, 27 respectively is a continuous drive tape 141 having therein'a series of latory and reciprocally translatory motion of the gears 122, 161 will cause teeth 124, 163'thereof to' progressively AS gear 22 undergoes this motion, gear teeth 24 will progressively engage successive openings 42 in cylindrical.

driven element'41 so that the pitch diameter of gear 22 efiectively rolls around the interior surface of driven,

element 41.

Because driven cylindrical wall, instead of an internal gearas in the prior art, the number'of eifective teeth "(that is, spaces beele'ment 41 is inthe form of a. thin tween openings) of element'41 may be as few as one 'more than the number of teeth on driving gear 22. In this eventyfor' every rotation of motor shaft 16 cylin-' engage the openings'142 as .thetpitchline's of gears 122', a 161 effectively roll along the inner surface; of the semi I "circular arcuate portion of belt 141 .1

Due to the 180 phase displacement of eccentric 119 and gear 122 with respect to eccentric 160 and gear'161,

it will be seen that for one-half the cycle of rotation of shaft16 tape 141 is engaged by gear 122 whereas for the V other half cycle ofrotation of shaft 16 ta e 141 is en; ga ged by the, other gear 161, the two gears thus alter nately driving tape 141which in turn ay be onnected ,7 to a pulley (notshown) or sprocket gear (not shown) td receive the power transmitted by tape 141' from shaft16 through gears 122,161;

Referring now to FIGS. 7 to 10 inclusive there isshow'n 5 still anotherrmo'dified form of the invention similar to the modification of FIGS.'4 to 6 described above exceptrthat a chain 241 is employed instead of the tape 141 of the previous modification.

More specifically,-chain 241 is alternately-engaged by gears 222, 261 which are simultaneously oscillated about d'rical drive element.41.isadvanced a disatnce of one tooth space by the action of gear 22 rolling in the manner. aforesaid. The power is thus transmitted from motor shaft 16 through eccentric 19 to gear 22 which ispturn V transmits the power to cylindrical driven element 41 and hence to pulley 45 from where the power is taken olT-by drive belt 49. i v 7 I V 7 Referring now 'to FIGS. 4 to 6 inclusive, .there is shown-V-a modified form '112 of the invention wherein those parts which are similar to corresponding parts'of' the modification of FIGS. 1 to 31are;given'thesame ref z erence numerals. The modified speedi eduction driven mechanism indicated generally by the reference numeral 112 compris'es' a sleeve member 117secured by a set.

screw 18 to a motor shaft 16 projecting from a housing 14' of an electric motor 13. -Sleeve member 117, like its counterpart indicated at 17 in FIGS. 1 to 3, is provided with an eccentric'disk 119 similar to disk 19 described motions of gears 222, ,261 g each other. 7 a a V Each of gears 222, 261 is'provided with an elongated 7 slot 225 extending radially withjrespect to the axis 21 of above but approximately one-half as thick; A second eccentric disc 160 is formed integral with sleeve 117 and has its center displaced 180 from thecenter of disk 119.

a That is, the' eccentric throw of'disc 11 9 isi'in the opposite direction to that of disk 160,'for a purposetobecome apparent., g *A first gear 122 similar t'o gear 22 but'preferably half a as thin is provided with a circular opening 123 receiving disk 119 which drives gear 122, and a second gear' 161 is similarly provided with an opening 162 receiving} the f econd eccentric disk 160 was to-be driven by the latter. 1 -Itw-ill be noted that each of gears 1 22, 161fis provided withgear teeth at 124,163 respectively only throughout, an arcuate segment of 180, I

, is provided with circular clearance holes 229 through which'said pin assemblies may project without obstructing the movement of gear; 222, and the other gear 2611s the axis ofpin'asse'mbly 28, 31,32 and reciprocably' translated'in the radial direction whereby the teeth 224$ 263 will progressively engage, the spaces 242 between the roller sleeves 243 of' chain 241. 'Gear 222 is provided r with a central opening 223 which receives a circulareccentric disk 219 formed integral with a sleeve 217 secured to motor shaft 16 by a set screw 18. Also formed integral with sleeve 217 is a second circular eccentric disk 260 received xwithin a circular opening ,262 formedfin gear 261; As noted'above with respect-t0 the previous modi fication," eccentric disks 219,260 are displaced 180 or one-half' cycle of rotation apart so that the respective",

' are 180 out of phase with motor shaft 16; A pin assembly extends through both slot 225 and comprises a spacer sleeve/28, bushing 31 and bolt 32,"as described above. Three other pin'assem blies extend through suitable openings formed in housing plates 226, 227 to'maintain the latter in assembled relation on the side face 35 of motorhousing 14.} Gear222 similarly provided with circular openings 230 for the arcuate portionof chain 241 with the gear teeth 224,263 1 1 progressively engaging the spaces 242' of chain 241th.)

same purpose.

-As motor shaft 16 rotates,eachof gears 222, 1 u undergo a combined oscillatory and reciprocally translar tory motion so as to roll with respect to the semi-circular spaced'o'penings 142 adapted to engageably receive the f teeth 124, 163 of gears 122,161- ;The combined oscildrive the latter; Due to the 180 phase. difference between eccentric disks 219; 260 gear 222 will engage chain 241 during one half-cycle of rotation of motor shaft 16 and the other gear 261 will engage chain 241 for'the'other half-cycle of rotation of motor shaft 16; Chain 241. will thus be advanced a distance of one tooth space for' each rotation of motor shaft 16 if the diiference'between the number ofteeth (or spaces) of chain 241 present in a length thereof equivalent to its pitch :circumfererice and the number of gear teeth 224, 263'is one, and chain 241 will be'adv'anced a distance of two tooth spaces if said difference is two. l a

Chain 241 may be of any conventional or other suitable construction and is disclosed for purposes of illus: tration as comprising a first'series of links 244 each having at its opposite ends an opening receiving a sleeve 245 mounted on one end of a pin 246 having at its'opposite end sleeve 247 receive within anopening formed in the ends of a second series of 248 extending parallel to said first series 244; A third'sefies" of links 249 is provided at its opposite endswith openings receiving the respective sleeves 245. is staggered with respect tothe series 244l similarly afourth series of links 250 is staggered with respect to a second series 248 and is provided with openings at opposite ends receiving the respective sleeves 247. Heads 252 are fixedly secured at opposite ends of pins 246 by screws 253. Rollers 251 at opposite ends of each pin 246 are rotatable thereon to reduce friction by rolling along the peripheral edges of housing plates 226, 227. Alternatively, chain 241 may drive a pulley 280 as shown in FIG; 10. For this purpose, heads 252 may be conical so as to match the inclination of the side walls 281, 282 of the V-shaped groove formed by the two halves 283, 284 of pulley 280.

i There are thus disclosed several embodiments of the invention wherein a high transmission ratio is provided in a speed reduction drive mechanism which is nevertheless compact, economical in manufacture, and reliable and durable in operation.

It is to be understood that the specific embodimentsof the invention shown in the drawings and described in detail above are merely illustrative of several of the many forms which the invention may take in practice without departing from the scope thereof as delineated in the ap-.

pended claims and that the claims are to be construed as broadly as permitted by the prior art.

I claim:

1. A speed reduction drive mechanism comprising a stationary support, a motor, a member rotatable on said support about the axis of rotation of said motor, means for drivingly connecting said member to said motor, a

However, said third series 249 means drivingly connecting saidmember tosaid'moto'r including a motor shaft for said motor, said plates having aligned openings therethrough for receiving a motor shaft. -3.'A mechanism as recited in claim 1 wherein said power take-01f means comprises a pulley secured 'to said' driven element, and a' belt in'driv'i'ng engagement with said' pulley; and wherein said membercomprises a sleeve adapted to be mounted on said'mot'or shaft and said motor shaft extending through said sleeve} 4. A speed reduction drive mechanism" comprising a stationary support, a member rotatable about an axis of rotation, means for drivingly 'Eonnecting-said member to a motor, a circular eccentric disk fixed to said member and eccentn'cally located with'respect' to sai'd'axis, a gear having teeth at -the periphery thereof and having a circular central opening receiving said eccentric disk and having an elongated slot therethrough extendingradially with respect to said axis, pin means secured to said support and extending into said slot, and a continuous curvilinear' driven element extending around atleast approxi mately half the peripheryof said gear and having a series f-spaced openings therethrough for drivingly engaging said teeth?" 5. A mechanism as recited in claim 4 wherein said driven element comprises a cylindrical wall surrounding said gear, said wall having said series of openings therethrough.

6. A mechanism as recited in claim 5 and comprising a pulley. secured to said cylindrical wall, a belt in driving circular eccentric disk fixed to said member and eccentrically located with respect to said axis, a gear having teeth at the periphery thereof and having a circular central opening rotatably receiving said eccentric disk and having an elongated slot therethrough extending radially with respect to said axis, pin means secured to said support and slidably extending into said slot, a continuous curvilinear driven element extending around said gear and having a series of spaced openings therethrough for receiving said teeth, the number of teeth in the gear being diflerent than the number of openings in said element, whereby rotation of said member .will cause combined oscillatory and reciprocal translatory motion of said gear to provide progressive interengagement of said teeth with said openings and thereby drivingly rotate said element, and power take-oflf means drivingly connected to said element.

2. A mechanism as recited in claim 1 wherein said support comprises a pair of mutually spaced parallel plates, means for mounting one of said plates to a motor engagement with said pulley, said support comprising a pair of mutually spaced parallel plates, means for mounting one of said plates to a motor housing, and means for securing the other plate to said one plate, said eccentric disk and said gear being located between said plates so as to be housed by the latter, said plates having aligned openings therethrough for receiving a motor shaft.

7. A mechanism as recited in claim 4 and comprising a second circular eccentric disk fixed to said member and being eccentrically ofiset with respect'to said axis in a direction opposite to that of said first-recited disk, and a second gear having teeth around at least approximately half the periphery thereof and having a circular central opening receiving said second eccentric disk and having'a second elongated slot therethrough receiving said pin means, whereby the teeth of said first gear progressively engage said driven element openings during one-half of each cycle of rotation of said member and the teeth of said second gear progressively engage said driven element openings during the other half of each cycle of rotation of said member.

a 8. A mechanism as recited in claim 7 wherein said driven element comprises a flexible tape.

9. A mechanism as recited in claim 7 wherein said driven element comprises a flexible chain.

10. A speed reduction drive mechanism comprising a stationary support, a member rotatable about an axis of rotation, a gear having teeth at the periphery thereof, means mounting said gear for combined oscillatory and reciprocating translatory movement with respect to said support, means drivingly connecting said member and said gear for oscillating and reciprocally translating the gear in response to rotation of said member, an annular element having a cylindrical wall surrounding said gear, said wall having a series of spaced openings therethrough for receiving said teeth, whereby rotation of said member will cause combined oscillatory and reciprocal translatory motion of said gear to provide progressive interengagement of said teeth, with said openings and thereby drivingly rotate said element, and power take-off means drivingly connected to said element.

11. A mechanism as recited in claim 10 wherein said power take-oif means comprises a pulley secured to said annular element, and a belt in drivingengagement with said pulley, and wherein said member comprises a sleeve through; V o a V I 12. A speed-reductiondrive mechanism comprising a V stationary supportya member rotatable about an axis of adapted to bezmounted on a motor shaft extending thererotation, a gear having teeth-atthe periphery thereof, means mounting said gear for combined oscillatory and reciprocating translatory movement with respect to said support, means drivingly connecting'said member and said gearfor simultaneouslyoscillating and reciprocally trans-g lating the gear in response "to rotation of said member; and a continuous curvilineardriven element. extending around at least approximately half the periphery of said gear and having a series of spaced openings therethrough member and 'said second gear for simultaneously oscillatirig'iand reciprocally translating the second gear in response to rotation of saidmember, whereby the tee th of said'first gear progressively lengage saiddriven ele ment openings during one-half of eachcycle of rotation of said member and the teeth of said second-gear pro- 7 gressively. engage said ,drivenl elementopenings during the other half of each cyele'of rotation of said member;

, 15. A mechanismvas recited in c1airn314 wherein "said a driven element comprises a flexible. tape, v

1 16.. A mechanism recited .iniclaim 14 wherein said driven element comprises a flexible chain. 7

, a V o .20 means mounting said second gear for c0mb1ned-oscil lator'y and reciprocating translatory movement' with respect to the support, 'means drivingly connecting said ReferencesfCitedby'the Examiner I VVUNVITIEDV, STATES PATENTS v 1 128,352- 6/77 Andrevvs 74- -805 l 3,14s,5s5 8/64 Brown V 74-805 FOREIGN PATENTS r 824,705 8/47 France. V DON, A. WAITE,"Ptiniary Examiner. i 

1. A SPEED REDUCTION DRIVE MECHANISM COMPRISING A STATIONARY SUPPORT, A MOTOR, A MEMBER ROTATABLE ON SAID SUPPORT ABOUT THE AXIS OF ROTATION OF SAID MOTOR, MEANS FOR DRIVINGLY CONNECTING SAID MEMBER TO SAID MOTOR, A CIRCULAR ECCENTRIC DISK FIXED TO SAID MEMBER AND ECCENTRICALLY LOCATED WITH RESPECT TO SAID AXIS, A GEAR HAVING TEETH AT THE PERIPHERY THEREOF AND HAVING A CIRCULA CENTRAL OPENING ROTATABLY RECEIVING SAID ECCENTRIC DISK AND HAVING AN ELONGATED SLOT THERETHROUGH EXTENDING RADIALLY WITH RESPECT TO SAID AXIS, PIN MEANS SECURED TO SAID SUPPORT AND SLIDABLY EXTENDING INTO SAID SLOT, A CONTINUOUS CURVILINEAR DRIVEN ELEMENT EXTENDING AROUND SAID GEAR AND HAVING A SERIES OF SPACED OPENINGS THERETHROUGH FOR RECEIVING SAID TEETH, THE NUMBER OF TEETH IN THE GEAR BEING DIFFERENT THAN THE NUMBER OF OPENINGS IN SAID ELEMENT, WHEREBY ROTATION OF SAID MEMBER WILL CAUSE COMBINED OSCILLATORY AND RECIPROCAL TRANSLATORY MOTION OF SAID GEAR TO PROVIDE PROGRESSIVE INTERENGAGEMENT OF SAID TEETH WITH SAID OPENINGS AND THEREBY DRIVINGLY ROTATE SAID ELEMENT, AND POWER TAKE-OFF MEANS DRIVINGLY CONNECTED TO SAID ELEMENT. 